Apparatus and method for purifying polluted water

Abstract

In a polluted water purifying method and apparatus, a purification treatment tank is filled with massive purifying members in a purifying region, each massive purifying member including plural opening portions having an equivalent diameter of 1 to 5 cm which are provided on the surface thereof, and plural interconnecting channels which intercommunicate with one another and provided inside of the members, and each opening portions continuously intercommunicating with at least one of the channels. Polluted water containing SS, BOD, etc. is supplied through the purifying region of the tank to be brought into contact with the massive purifying members. At the same time, oxygen-contained gas is jetted as fine bubbles at a predetermined interval from the bottom portion of the purifying region into the polluted water so that the stream of the flowing polluted water flowing in the purifying region, so that the fine bubbles of the oxygen-contained gas are contacted with the polluted water in a substantially perpendicular direction to each other, whereby an aerobic treatment and an anaerobic treatment are rapidly and efficiently performed on the surface of the purifying members and inside of the purifying members respectively.

What is claimed is: 
     
       1. A polluted water purifying method comprising the steps of: filling a purifying region of a container with massive purifying members containing a plurality of surface openings, each having an equivalent diameter of from about 1 cm to about 5 cm and a plurality of internal mutually intercommunicating channels, each of said openings communicating with at least one of said channels; and   passing a stream of polluted water through said purifying region of said container in contact with said massive purifying members while simultaneously passing oxygen-contained gas as fine bubbles in a plurality of streams located at spaced intervals of from about 5 cm to about 100 cm along the stream of polluted water and directing said oxygen-contained gas into contact with overlying massive purfying members substantially perpendicular to said polluted water stream so that the stream of the flowing polluted water is brought into contact intermittently with the streams of fine bubbles of the oxygen-contained gas thereby treating the water by a purification treatment.   
     
     
       2. The polluted water purifying method as claimed in claim 1, wherein said purifying region is formed between a flow-in portion from which the polluted water flows in, and a flow-out portion from which purified water flows out. 
     
     
       3. The polluted water purifying method as claimed in claim 2, further comprising the step of rectifying the polluted water at said flow-in portion and/or said flow-out portion. 
     
     
       4. The polluted water purifying method as claimed in claim 1, wherein the polluted water is retained in said purifying region for a period between 10 to 120 minutes. 
     
     
       5. The polluted water purifying method as claimed in any one of claims 1 to 4, wherein the predetermined interval is set to be variable in the range in accordance with pollution degree of the polluted water to be treated. 
     
     
       6. The polluted water purifying method as claimed in claim 1, further comprising the step of thereafter passing the water treated in the purification treatment into a non-gas-diffusion purifying region filled with said massive purifying members. 
     
     
       7. The polluted water purifying method as claimed in claim 6, wherein said non-gas-diffusion purifying region is disposed in said purifying region of said container downstream of said stream of oxygen-contained gas and upstream of said flow-out portion. 
     
     
       8. A polluted water purifying apparatus, comprising: a container having a peripheral wall defining a predetermined volume;   a flow-in portion for polluted water at one end of said container, and   a flow-out portion for treated water at another end of said container;   a rectifying member disposed at each of said flow-in portion and said flow-out portion generally defining paths of flow of polluted water through said container;   a purifying region in said container disposed between said flow-in portion and said flow-out portion and traversed by said paths of flow of polluted water;   a plurality of massive purifying members substantially filling the purifying region in said container, each of said massive purifying members containing a plurality of flow conducting passages including a plurality of openings on the surfaces of said members having an equivalent flow conducting diameter of from 1 to 5 cm and a plurality of interconnecting channels intercommunicating with one another inside of said massive purifying members, each of the openings intercommunicating with at least one of the interconnecting channels; and   gas diffusion pipes disposed at predetermined intervals of from about 5 cm to about 100 cm in said container beneath said polluted water flow paths and being operative to jet a plurality of spaced oxygen-contained gas streams into contact with overlying massive purifying members in said container in a direction substantially perpendicular to said polluted water flow paths.   
     
     
       9. The polluted water purifying apparatus as claimed in claim 8, wherein each of said massive purifying members comprises a plurality of aggregates bonded to one another and formed in a substantially spherical shape having an equivalent diameter of from about 7 to about 15 cm. 
     
     
       10. A polluted water purifying method for utilizing the polluted water purifying apparatus as claimed in claim 8, wherein the polluted water is introduced into said container from said flow-in portion and passed through said purifying region while oxygen-contained gas is diffused from said gas diffusion pipes at a front stage portion of the container adjacent the flow-in portion side of said purifying region and no oxygen-contained gas is diffused from said gas diffusion pipes at a subsequent stage portion of the container adjacent the flow-out portion side of said purifying region to thereby perform the purifying treatment. 
     
     
       11. The polluted water purifying method as claimed in claim 10, wherein said purifying region is sectioned by said front stage portion and said subsequent stage portion in a sectioning ratio of 1:1 to 5:1. 
     
     
       12. A polluted water purifying apparatus including first and second purifying apparatuses, each of which apparatuses includes a container having a flow-in portion for polluted water, a flow-out portion for treated water, a purifying region disposed in said container between said flow-in portion and said flow-out portion whereby rectifying members generally define paths of flow of polluted water between said flow-in portion and said flow-out portion, gas diffusion pipes disposed at predetermined intervals of from about 5 cm to about 100 cm along said purifying region beneath said polluted water flow paths and being operative to disperse gas in a direction substantially perpendicular to said polluted water flow paths, and massive purifying members substantially filling the purifying region of said container, each of which massive purifying members contains a plurality of flow conducting passages including a plurality of openings on the surfaces of said members having an equivalent flow conducting diameter of from about 1 to about 5 cm and a plurality of interconnecting channels intercommunicating with one another inside of said massive purifying members, each of said openings intercommunicating with at least one of the interconnecting channels, said massive purfying members overlying said gas diffusion pipes being operative to be contacted by gas from said gas diffusion pipes in a direction substantially perpendicular to the direction of contact of said massive purifying members by said polluted water, and wherein said flow-out portion of said first purifying apparatus and said flow-in portion of said second purifying apparatus intercommunicate with each other. 
     
     
       13. A polluted water purifying method for utilizing the polluted water purifying apparatus as claimed in claim 12, wherein the polluted water is supplied from said flow-in portion into said purifying region of said container of said first apparatus to pass the polluted water through said purifying region thereof while the oxygen-contained gas is diffused from said gas diffusion pipes of said first purifying apparatus to perform a purification treatment on the polluted water, and the purified water is supplied from said flow-out portion of said first purifying apparatus to said flow-in portion of said second apparatus to perform a further purification treatment on the purified water supplied from said first purifying apparatus in said second purifying apparatus while no oxygen-contained gas is diffused from said gas diffusion pipes of said second purifying apparatus.